In a typical agricultural seed planter, a plurality of seed meters are arranged in a row corresponding to furrows to be seeded. Such a seed planter is disclosed in U.S. Pat. Nos. 6,308,646 or 6,644,225. Each seed meter is supplied with a supply of seeds. A seed meter disk is rotated within the seed meter in communication with the supply of seeds while a vacuum is applied to an opposite side of the disk. The seed meter discharges seed at a predetermined rate along the furrow. Such a seed meter is disclosed for example in U.S. Pat. No. 5,170,909.
To supply the vacuum to each seed meter, a vacuum pump is arranged on the seed planter. Typically, the vacuum pump used on agricultural seed planters is an off-the-shelf centrifugal fan or blower implemented in such a manner to generate the needed vacuum. These pumps can be large and cumbersome.
The current vacuum pump design for a JOHN DEERE 1700 series planter uses a typical centrifugal fan design with a scroll housing. In such a design, the outlet of the impeller is channeled into a single channel by the impeller housing. The vacuum pump is driven by a hydraulic motor. The current vacuum pump assembly for a JOHN DEERE 1700 series seed planter must be rotated at over 8000 rpm to achieve the necessary pressure drop for the vacuum seed meters to plant the larger corner-condition crops. This rpm requirement can necessitate a costly hydraulic motor for the vacuum pump.
Furthermore, the current JOHN DEERE 1700 series seed planter centrifugal blowers require a special tool to remove the impeller from the hydraulic motor output shaft.
The present inventor has recognized that a need exists for an improved seed meter vacuum pump that can generate sufficient pressure drop or vacuum to dispense larger “corner-condition” crops using vacuum controlled seed meters, at an rpm within a usable range for a cost effective hydraulic motor. The present inventor has recognized that a need exists for a seed meter vacuum pump that can generate an increased pressure drop compared to current centrifugal air blowers used on seed planters, while retaining a compact size.
The present inventor has recognized that a need exists for a seed meter vacuum pump that is easily maintained, including being easily assembled and disassembled.